The present invention relates to a safety alarm device and more particularly to a portable, self-contained alarm device adapted to be worn on the user's hand for providing an alert signal when, through drowsiness or otherwise, the individual's hand relaxes.
There are a number of devices that may be worn on or about the body to sense the wearer's alertness and to sound an alarm when the alertness level diminishes. One such device is shown in the U.S. Pat. No. 4,059,830 which includes a sleep alarm device worn on the user's hand to prevent him from falling asleep while smoking in bed or while driving an automobile. The device includes two metal rings worn on adjacent fingertips, like thimbles, and connected by an elastic band. The user must stretch his fingers apart against the pressure of the elastic band to keep the two thimbles from touching and sounding a buzzer. Stretching the fingers apart in this manner is difficult for most people and is likely to quickly tire the user's hand.
In U.S. Pat. No. 3,861,349, an operator alerting device is disclosed which includes a glove worn on the user's hand to which is attached a needle arrangement for pricking the flesh of the wearer should his hand slip from the wheel and rest, for example, against his thigh. A similar device is disclosed in U.S. Pat. No. 3,964,045, which includes a glove-type arrangement to which one end of a cord is attached while the other end of the cord is attached to the switch of an alarm device mounted on the vehicle above the steering wheel. The length of the cord is adjusted so that it is loose when the operator's hand is on the steering wheel but becomes taut when the operator's hand drops, for example, to his or her thigh creating a tension on the switch which operates the alarm device. This apparatus requires the operator to be connected to his vehicle in what could be a clumsy fashion, especially if the operator attempts to turn the wheel.
In the past, various kinds of fingertip controls have been suggested which permit remote operation of various kinds of devices. In U.S. Pat. No. 1,296,088, a fingertip attachment is disclosed which permits the operator of a car to blow the horn without lifting his hand from the perimeter of the steering wheel to the center of the steering wheel, where the horn is often located. A similar type of device which permits the user to activate a machine by closing his hand around the handle is shown in the German Pat. No. 1,193,583.
Other devices sense the motion of the operator's head to initiate an alarm condition as, for example, connecting a mercury-type switch to the driver's eyeglasses, so that when the head tips, the switch activates an alarm and turns off the ignition (U.S. Pat. No. 3,953,831) or a switch supported under the driver's chin by means of a hook which can be attached to the driver's clothing, so that when the driver's head tips the switch is activated and sounds an alarm. (U.S. Pat. No. 3,054,868) Because these devices appear to require a driver to concentrate on keeping his head still to avoid erratic triggering of the alarm, it appears that they could add to the fatigue which they are intended to protect against and inhibit his normal activity.
There is a need for a portable, self-contained, ruggedly constructed alarm device which may be comfortably worn by the user without fatigue and without unduly confining his normal activity. It is also desirable that the device not require connection to the vehicle which is being operated by the user.